Abstract

The thin-disk laser configuration, which allows for particularly efficient high power lasers, demands an active medium with high doping levels in order to achieve sufficient absorption within the thin disk. Yb³⁺-doped YAG is a very suitable medium for this application because it offers a high doping potential and superior thermo-physical properties. The simple energy level scheme of the Yb³⁺-ion prohibits quenching processes such as cross-relaxation and up-conversion. However, Yb:YAG thin-disk lasers suffer decay processes that generate heat and inhibit laser operation at high doping concentrations and inversion densities [1]. These processes depend on the excitation density in the active medium and reduce the laser efficiency of Yb:YAG crystals even at conventionally low doping concentrations [2]. Additionally it has been found that Yb:YAG ceramic active media display higher efficiencies and a lower sensitivity to the Yb-excitation dependent losses than single crystalline active media [3].

© 2013 IEEE